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Steam Boiler Low Pressure
I hope I'm not breaking any forum rules, but saw that my issue wasn't getting any love any more:
https://forum.heatinghelp.com/discussion/175351/no-pressure-from-steam-boiler-compared-to-last-year#latestBoiler has lower pressure compared to last year. Ruled out main vents, gas firing rate is correct, no leak in boiler itself (1hr 15min test filled to over top), no leaks at radiator supply valves, no water in gauge assembly.
No air puffing from Gorton main vent like last year (replaced it too). Main vents do get hot. I have one known sagging pipe and its radiator intermittently heats. Could this pipe be condensing so much water that the pressure would not build up?
Any recommended tests to help further troubleshoot or any known ways this can possibly happen?
Thanks for the help!
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Comments
Yes. But fill me in on this: Why do you care that your pressure isn't going up? You said your radiators were getting hot to comfortably heat your living space, right?
So... I would look at it this way: if the system is heating well (except that one problem child) and reasonably evenly, and water consumption is normal (that is very small), it's doing what it's meant to do. So to go back to the top -- why was the pressure higher last year?
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
Why did it have higher pressure last year? My thinking is either 1. that the steam was restricted only by the vent holes, and pressure rose when the main vents closed and now it's going out another hole. Or 2. The boiler isn't producing the same amount of steam for the same gas rate. Problem 1 I can get my head around, but need help in techniques to find the leak. Problem 2 I'm looking from input from the forum if anyone has ever seen anything like it.
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
As far as cleaning the pigtail assembly. I removed the gauge at "A", and removed the plugs at B, C and D. Some water came out from B and C. Closed B and C, and blew into A, and could feel air at D. Concerning the port at D and its vertical pipe into the boiler, when I filled the boiler above the top, I used this to see the water level. I let the water level get to the green line. When I drained the boiler back to the usual water line, the water left that tube, so I'm assuming its clear unless there is some sort of trap there? Also, I had blown into the gauge, and got the needle to move up.
It has a two stage gas valve, and it has not cycled to the lower stage this season yet. Also the main vent that used to make a huffing noise last year before it closed, is silent now.
"Reducing our country's energy consumption, one system at a time"
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Baltimore, MD (USA) and consulting anywhere.
https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
When a knowledgeable steam guy comes and perfectly sizes your boiler the view is different, you now see 0 to a few ounces of pressure, steam condenses at the radiators and creates a vacuum and more steam enters, only half of the radiator heats up, the vent almost never get hot making them last longer, thermostat is satisfied
Now, on design day, (very few in a year) radiators will
completely get hot and you will see pressure climb up
Steam is less dense than air, so it will want to flow to the radiators just by gravity. You only need enough pressure differential to overcome friction in the header and the fall in the header (parallel system). It’s almost like it’s pulled towards the cool metal in a vapor system.